Dispersion RAFT polymerization of 4-vinylpyridine in toluene mediated with the macro-RAFT agent of polystyrene dithiobenzoate: effect of the macro-RAFT agent chain length and growth of the block copolymer nano-objects
作者：Meihan Dan, Fei Huo, Xu Zhang, Xiaohui Wang, and Wangqing Zhang*
關鍵字：RAFT polymerization
論文來源：期刊
具體來源：Journal of Polymer Science Part A: Polymer Chemistry
發表時間：2012年
The dispersion reversible addition-fragmentation chain transfer (RAFT) polymerization of 4-vinylpyridine in toluene in the presence of the polystyrene dithiobenzoate (PS-CTA) macro-RAFT agent with different chain length is discussed. The RAFT polymerization undergoes an initial slow homogeneous polymerization and a subsequent fast heterogeneous one. The RAFT polymerization rate is dependent on the PS-CTA chain length, and short PS-CTA generally leads to fast RAFT polymerization. The dispersion RAFT polymerization induces the self-assembly of the in situ synthesized polystyrene-b-poly(4-vinylpyridine) block copolymer into highly concentrated block copolymer nano-objects. The PS-CTA chain length exerts great influence on the particle nucleation and the size and morphology of the block copolymer nano-objects. It is found, short PS-CTA leads to fast particle nucleation and tends to produce large-sized vesicles or large-compound micelles, and long PS-CTA leads to formation of small-sized nanospheres. Comparison between the polymerization-induced self-assembly and self-assembly of block copolymer in the block-selective solvent is made, and the great difference between the two methods is demonstrated. The present study is anticipated to be useful to reveal the chain extension and the particle growth of block copolymer during the RAFT polymerization under dispersion condition. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
onlinelibrary.wiley.com/doi/10.1002/pola.26527/abstract